Litter box



FIG. 1 is a front perspective view of a litter box showing my new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a side elevational view thereof;

FIG. 4 is an end view thereof with the opposing end view being the same view thereof; and,

FIG. 5 is a bottom plan view thereof. 

The ornamental design for a litter box, as shown and described. 